Furnace.



PATENTED OCT. 6. 1903.

H. B. GARY.

FURNACE.

APPLICATION nun JAN. 12, 1900.

2 SHEETS-SHEET 1.

N0 MODEL.

- its. 746,529.

' UNITED STATES} .iatented October 6, 1903.

PATENT OFFICE.

HENRY BOUNDS CARY, OF Los ANGELES, oALiroRivIA, ASSIGNOR TO FREDERICK w.BRAUN, or Los ANGELES, CALIFORNIA.

FURNACE.

SPECIFICATION forming part of Letters-Patent No. 740,528, dated October6,1903.

' Application filed Jamm 12. 1900. Sea in, 1.20s. on model.)

To aZZ whom it inaygncern; 7,

Be it known that I, HENRY BoUNDsQARY, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and. V

State of California, have invented a new and useful Furnace, of whichthe following is a specification.-

My invention is applicable to furnaces of various kinds, but isespecially adapted for use in assayers furnaces and the like requiringintense heats.

An object of my invention is to produceas complete combustion aud'asintense heats as may be practicable with the fuel burned in the furnace.

Another object of my invention in its use in assaye'rs furnaces is toprovide a superior muffle-furnace. In carrying'out: my invention in thisregardlprovidea muffie-furnace having a muffle for melting the chargesand having another muffle for on peling.

A further object of my invention is to provide for a considerableextension of a flame of intense heat, The flame produced by the use ofmy invention becomes practically invisible when the furnace is inoperation, with gasolene as a fuel applied through a suitable burner ofthe open Bunsen type.

My newly-invented furnace in its preferred I form for assay-furnaces isshown in the ac companying drawings as being provided with a pluralityof combustion-chambers which successively diminish in capacity and whichare connected in succession by contracted passages which successivelydiminish in crosssectional area. I have found that with a furnaceconstructed after the manner stated a flame can be produced in each of asucces sion of combustion-chambers aft-er the temperatures of suchchambers, respectively, have been brought to the igniting temperature ofthe gas supplied to them respectively.-

In actual practice the flameproduced in each of the successive chambersis practically-invisible, but of a very high temperature, and

the flame produced in any chamber completely fills the same, so that theinvention is especially adapted for heating muflies and large irregularsurfaces, for the reason that the flame envelope the muffle or othersurface to be heated, so that the muffle will heat on the top and sidesto substantially as high a degree as on the bottom or on the sideexposed to'the initial fire.

In the application of the invention for heating muffles my inventioncomprises a furnace provided with a primary combustiou-cham-- ber, asecondary combustion-chamber of less capacity than the primary chamber,a pas- "duced into a combustion-chamber and thence passed through acontracted passage to a chamber beneath a muffle or other body to beheated and thence through a contracted passage into a chamber whichsurrounds the upper part of the mufifie or other body to be heated,or-the initial fire can be introduced into a chamber immediately belowthe muffie or other body to be heated and thence through a contractedpassageinto the chamber which surrounds the upper part of the muffle orother body. For convenience in the description I will term the chamberbelow a muflie or like obstruction the primary combustion-chamber andthe chamber into which the products from said primary chamber areconducted for a subsequent combustion the secondary combustion chamber.The primary combustion-chamber may in some instancesbe the initialcombustion-chamber, while in other instances it may be thesecondary,terv.tiary, or quaternary coin bustion-chamher, or

a combustion-chamber still further removed from the initial chamber, andthe several secondary chambers may be secondary, tertiary, quaternary,or still further removed from the initial combustion-chamber into whichthe initial fire is introduced.

In carrying outmy invention it is prefer able to return the walls of thesecondary combustion-chamber inward to form the walls of the mouth ofthe outlet from such chamber,

. with cavities of the chamber on opposite sides,

respectively, of said mouth.

My invention relates to means for producing combustion in thoroughaccordance with philosophical and scientific principles, which I willnow set forth,- to wit:

The purpose of this invention is to bring into actual contact a maximumpercentage of the various combustible constituents of any fuel whichwill chemically unite to produce heat. It is my purpose to practicallyexhaust the heat-producing elements of any given fuel inany kind offurnace for any purpose for which high temperatures are practicable. Thephenomenon known as combustion results from the contact of quantities ofoxygen with quantities of carbon or hydrogen. These substances will onlymix and make chemical union when furnishedin quantities denoted as theirchemical equivalents, the

chemical equivalents being oxygen, eight;

carbon, six; hydrogen, one. They will only chemically combine in theseor multiples of these chemical equivalentsthat is to say, the chemicalequivalents of oxygen and carbon are as eight to six and those of oxygenand hydrogen are as eight to one.

gas and the oxygen occurs in larger quanti-.

ties, and when the quantity of oxygen comes in contact with the quantityof carbon combustion takes place between the two quantities so far astheir contact is produced; but the very product of the combustion, if itbe in proper portions, produces a dioxid which encystsand separates theremaining part of the oxygen from the remaining part of the carbonthatis to say, each of the remaining quantities of oxygen and carbon isencysted in a non-combustible gas of dioxid. The fact that combustion ofa part of the oxygen and carbon has taken place demonstrates anexcessive expansion of volume. Consequently if the volume be inapartially-inclosed space, like a furnace or fire-box, the gases thereincontained (being the product of .the combustion) must produce a certainpressure within the space, holding the remaining particles of oxygen andcarbon in suspension, but not in contact with each other. Now by passingthis product through a contracted Combus-v tion between oxygen andcarbon is produced exit into a chamber which is larger laterally thanthe exit and of a capacity proportionate to that of the prior fire-boxthe expansion of these gases is allowed, and in that expansion a generalchange of locality of the dioxid and the unconsnmed oxygen and carbonparticles ensues. Now by a proper construction and arrangement of thechamber, its inlets and exits, in which this expansion is allowed, theuneonsumed oxygen and carbon particles can be brought into contact witheach other and an ignition and combustion produced. In order to producethis mixture, it is necessary that the chamber, with its entrance andexit, be so constructed as to maintain a required pressure upon thegasesand also to produce within the chamber opposing currents for generalmixing up of the gases. In the mixing and combustion chamber while theexpanded gases are impinging upon the contents of such chamber, whichare being partially held by the construction of the resisting walls ofthe chamber,a general breaking up of the columns of the gases must occurand another mixing of the gases takes place, and the required pressureis sustained, and these particles of unconsumed oxygen and carbon whichcome in contact will ignite, producing results corresponding to thoseproduced in the first chamber. By repeating the same process of exit andexpansion and remixing further combustion is produced.

From extensive experiments made it requires at least four mixing andcombustion chambers to entirely exhaust the combustible materials ofhydrocarbon gas and oxygen when introduced to a furnace by the latestand mostapproved methods. After the expansion, which results at themoment of combustion, the particles of thecombustibles being surroundedby the dioxid product of the combustion,and thereby separated from eachother, are incapable of further combustion until the encystment isbroken up and the combustible particles are brought together in theappropriate proportions and at the required temperature. This breakingup of the product and reuniting the combustible elements is accomplishedby passing the product through an exit of smaller dimensions than thefirst combustion-chamber and dischargingit into anothercombustion-chamber of greater cross-sectional area than the exit and ofa definite capacity.

It is essential in carrying out myinvention that the interior of thefurnace must be so constructed that vapor-mixing combustionchambers areformed appropriately, as distinguished from any arrangementof lines infurnaces heretofore known, for carrying off the heat and the products ofcombustion. In order that successive combustions shall take place, thepassages and chambers must be so constructed as to remix the gases orvapors.

It is not sufifiicient in carrying out my invention that-a fine besimply provided with a greater or less number of enlargements and ICC 5hausted no increase or change in temperacontractions. The walls of theenlargements or chambers and theinlets and outlets from such chambersmustbe constructed and arranged to successivelyproduce a contraction, anexpansion, and a backward deflectionof the gases and vapors thus toremix thesaid vapors and gases in the successive enlargements or mixingand combustion chambers for breaking up and remixing in the respec-'tive chambers the columns of gases and vapors which enter said chambers,respectively, from their'immediately preceding chambers, respectively. IBy extensive experimen is itwas found that in an initial fire'nothinglike perfect combustion could be obtained- The productof the mostperfect fire obtainable was found to 1 readily ignite again, althoughthe hydrogen and exits, could readily be estimated. .It mat-v wasabsent, the same being consumed in the initial fire. The temperaturefor-the sec ondary ignition had to be 'much higher to incite chemicalaction between the oxygen and carbon than in the first instance; but insuccessive instances of ignition until one or the other of thecombustibles was exture was required in the various combustion-chambers.It was found that the only requisite to again ignite the combustiblesremaining in the product of a previous tire was tosuddenly relieve thepressure upon the same and then return the gases upon themselves bydeflection, when the enveloping non-combustible gases would release thecaptive combustibles, (oxygen and carbon,) which'then by their naturalaffinity would again come in contact and if at an ignition temperaturecombustion would instantly ensue to all that were in contact in properproportions. To produce this result by mechanical constructioncontinuouslyin the one furnace or are: box vas found quite impossibleunless the character or quantity of the first or initial fire was takeninto the account; but when this was a known quantity the relativedimensions of the first, second, third, and fourth 'combnstion-chambers,with their several intakes ters not what fuel is used'if the initialfire is of snflicient quantity to raise to an ignition temperature thesecond chamber combustion there will instantly be the result, the samebeing true in the case of eachsubsequent chamber, so long as thereremains any quan- FigureI is a perspective view of a combi-" nationmelting and cupeling furnace. The cover for the crucible-chamber andthe-stopper for the muffle are omitted-from the view.

Fig. II is a planof this furnace on-a reduced" scale. Dotted linesindicate the'interior con struction. Fig. III is a vertical section online IIIIII, Figs. II and IV. Fig. IV is a.

vertical section on line IV IV, Fig. III. Fig.

V is a vertical section on line V V, Figs. VI, 7

VII, and VIII, illustrating a'combination muffle-furnace embodying myinvention. Fig. VI is a vertical section, on lineVIVI, Figs. V, VII, andVIII. Fig. VII is a plan section on line VII VII, Figs. V and VI. Fig.VIII is a plan section on line VIII VIII, Figs. V and VI. j c

In Figs. I, II,'III, and IV, a indicates the body of a combinationmelting and muflle f nrnace. 12 indicates the initial combustionchamber,the same being the crucible-pot of less capacity than the primarycombustion-' chamber d, and said primary combustionchamber (2. is ofless capacity than the initial combustion-chamber b.' 7?. indicates anoutlet from the secondary combustion-chamberg. This outlet may open'intoanother combustion-chamber, if desired. In the furnace shown in Fig. I4} indicates a flue leading' from the outlet 71. The passage 0 leadsfrom chamber 5 into chamber 61. In the practical construction ofafurnace of this character the muffle e is set in an opening between thecombustion-chambersd and g and partially closes said opening, sothat theunobstructed portion fof the'opening is ofgreater cross'sectional areathan the outlet'h from the secondary combustion-chamber g. The tops ofthe walls of the secondary combustionchamber g are preferably returnedinward toward the muffle to form the mouth of the outlet h, withcavities 1 2 on the opposite sides of said outlet, so that thecombustion-chamher 9 is contracted above the muffle at the outlet, asshown in Fig. III.

Referring to Figs. V, VI, VII, and VIII, a indicates'the body of thefurnace. 0! indicates a combined initial and primarycombustionchamber-'th at is to say,the combustion-cham- .ber d receivesthe initial fire and also serves as the primary combustion-chamber withrelation to the m uflie e. p g indicatesthe secondary combustion-chamberfor the muflie e. f

indicates the outlet-passage leading from the combustion-chamber dintothe' combustionchamber 9. hindicates the outlet leading fromthecombustion-chamber g'into'a primary combustion-chamber dfor amufflee, which forms the top' of the combustion-chamher-d in'the same mannerasthe' mufilee forms the top of the combustion-chamber d. f indicatesthe outlet from; the primary combustion-chamber 61 into the secondarycombustion-chamber g. h indicates the outlet from the secondarycombustion-chamber g. 1 2 indicate the cavities on the opposite sides ofthe mouth of the outlet 71.. 12" indicate the cavities on the oppositesides of the mouth of the outlet h. In the several views j indicatessupports for the inner ends of the muffle. It indicates a burner forsupplying the initial fire to the furnace.

In Figs. III and IV, m indicates the cover for the crucible-pot. 11indicates a pipe connecting between the muffles and the fine to carry 0%the fumes.

In practical operation the initial fire is introduced into the initialfire-chamber, and the flame proceeding therefrom through the contractedoutlet is first contracted and then is allowed to expand into thesucceeding combustion-chamber. When the combustionchamber intowhich theproducts of combustion are emitted has been heated to a sufficientlyhigh temperature, the products which enter the chamber become ignitedand'produceaflameofgreatintensity. Theproducts of this combustion areagain contracted by the succeeding outlet and are again allowed toexpand into a succeeding combustionchamber, and when such succeedingcombustion-chamber is heated to the igniting temperature for suchproducts another ignition takes place and the resulting flame heats suchsucceeding combustionchamber to a high temperature, and so on throughoutthe furnace.

By the arrangement shown in Figs. V, VI, VII, and VIII when the lowermnffie e is heated to a temperature sufficient for melting the chargesfor assayers Work the muffle 6 will be heated to the heat proper foronpeling, and this is accomplished with no greater expenditure of fuelthan would be required for heating the lower muffle independently of theupper muffle. In the form shown in Fig. I the muftie is readily heatedfrom the products of the flame which is required for heating thecrucible-pot b, and no more fuel will be required for heating both themuffle and the crucible-pot than would be required for heating thecrucible-pot alone.

Different kinds of fires-that is to say, fires made in difierent ways orwith different kinds of fuelwill require special sizes and numbers ofchambers, intakes, and exits for each. The great advantages of thisdiscovery are not only in creating a greater amount of heat by consumingso much larger per cent. of the fuel, but by extending the actualflamevof combustion over a much greater absorbing and radiating surface,also solving the smoke nuisance as it is absolutelyimpossible for anysmoke to pass the third cham ber after that has attained an ignitingtemperature'.

In taking assay-furnaces as illustrations for my invention it is not theintention to make any claim upon their previously-known construction orcombinations. It is well known that none of the heretofore-knowncombination meltingpots and muffle furnaces can bejoperatedsatisfactorily from one fire at one end of the same. It is also wellknownthat with former muffle-furnaces no muffle has ever heretofore beenheated to an equable temperature throughoutthat is to say, to the sametemperature at the top andv bottom. The bottom next to the fire beingmuch the hottest, the heat is transmitted through the cupel to theleadto raise the same to the proper degree of heat to oxidize. When thefumes rise to a cooler atmosphere in the upper part of the muffle, theoxid would precipitate and fall to its own or some othercupel, therebycausing imperfect cupeling. With my discovery applied to either theheretofore-known combination melting-pot and muffle-furnace or to thesingle or double furnace it makes each of those" inventions highlyuseful in obviating the above difliculties. With this invention theproduct of the fire required for melting is passed from themelting-chamber into a combustion-chamber beneath the mnffle, whereitignites. Its resultant product is passed to the nextcombustion-chamber above and around the sides and top of the muffleandis there ignited and producesadegree of heat so nearly the same asthat produced below the muffle that no difference in temperature can bedetected in the top, bottom, or sides of the muffle by calorimeter or bythe fusion-point of metals. The capacity of the combustion-chambers,their intakes, and exits can be so nicely adjusted to the initial fireused that when the melting-pot is maintained at a melting heat themuffle is and must be exactly at the temperature required for cupeling.The various forms of the combustion-chambers adopted in the drawings areonly to accommodate them to the external, internal, and structural formsand requirements of the previously-used assay-furnaces. Thegas-mixingcombustion-chambers can be made in any form to suit the requirements ofany case if they at all times provide for proper amount of expansionsidewise or upward, or both, and for the required deflection to returnthe gases or vapors upon themselves in the chamber and just proportionsare maintained. These combustionchambers must not be confounded withfines, smoke or heat passages, cavities made by bridge-walls, &c. Thereason is plain. It matters not how many times you may bend a bundle ofcords each cord will remain relatively parallel to its neighbors. So,also, will the columns of variousgases and solids as they are forcedaway from the flame, where they have been created by the innumerableexplosions produced by the chemical action of the combustibles upon eachother and which action is ordinarily termed combustion, into and throughthe various formsof lines. In contradistinction to such operation mycombustion-chambers permit the' instant expansion of these col- IIOumns, also impinging them upon the contents of the chamber, (whichischecked by the proper outlet at a proper distance from the intake,)and by these means the columns andencystments are entirely broken thepressure relieved, and the combustibles allowed to come in contact witheach other.

It is to be noted that the succeeding combustion-chambers are connectedby contracted passage-ways and are respectively broadly expanded and areclosed to atmospheric air between inlet and outlet, whereby the gasesemitted from a preceding chamber are first compressed in the passagewayand then allowed to suddenly expand into a succeeding chamber and thenagain compressed, thereby producing in succession the conditionsnecessary for igniting the gases with substantially an explosive effectin the succeeding chambers, respectively, elements which were notbrought to ignition in the preceding chamber or chambers. It is also tobe noted that where a series of superposed muffles are used,

.ceeding muffle and each muffle is surrounded by fire resulting from aprimary and a secondary combustion, so that the entire mutfle issurrounded by elements in active combustion. This intermixture andcombustion resulting from two currents being directed in substantiallyopposite directions occurs just before the mixture isintroduced into thenext combastion-chamber. In speaking of the two opposing currents itshould be understood that I refer to one fork of the flame which isturned, bent, or deflected back upon itself,

although there is considerable intermixing when the two branches onopposite sides of the muffler come together just before they enter thecontracted portion before they pass to the next chamber.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is

1. In a furnace such as described, a plurality of gas-mixingcombustion-chambers, each successive chamber connected with itspredecessor by a contracted channel the initial end of which is inadvance of and at an acute angle with the terminal portion of the wallof the chamber, and each chamber gradually increasing in area from theoutlet-passage of its predecessor and then gradually decreasing in areatoward its own outlet-passage to the succeeding chamber; whereby thegaseous products contained in each chamber and moving successively inthe general path of the draft ofthe furnace, are caused toreverberateagainst the draft-current to release oncysted constituentsand mix the same in due proportions to be ignited by the heat generatedby previous ignitions or explosions.

2. A furnace furnished with a primary com.-

ed outlet leading from said tertiary combustion-chamber thewalls of saidtertiary combustion chamber being returned inward toward the said outlettherefrom.

In testimony whereof I. have signed my 'name to this specification, inthe presence of two. subscribing witnesses, at Los Angeles, California,this 30th day of December, 1899..

HENRY BOUNDS CARY.

'- 'Witnesses: v

' JAMES R. TOWNSEND,

FRANcIs-M. TOWNSEND.

